Sea Urchin Spines Research Articles

Tissue bionics: examples in biomimetic tissue engineering

Many important lessons can be learnt from the study of biological form and the functional design of organisms as design criteria for the development of tissue engineering products. This merging of biomimetics and regenerative medicine is termed ‘tissue bionics’. Clinically useful analogues can be generated by appropriating, modifying and mimicking structures from a diversity of natural biomatrices ranging from marine plankton shells to sea urchin spines. Methods in biomimetic materials chemistry can also be used to fabricate tissue engineering scaffolds with added functional utility that promise human tissues fit for the clinic.

Sea Urchin Spine Arthritis of the Hand

Although rare, hand injury caused by puncture with the sea urchin spine can result in serious complications. To emphasize its clinical significance, this article describes a group of patients who sustained chronic granulomatous arthritis induced by puncture with sea urchin spine (designated sea urchin spine arthritis). Five patients who developed sea urchin spine arthritis of the hand after puncture with sea urchin spine were treated at our hospitals. All lesions involved the proximal interphalangeal (PIP) joint (4 index fingers and 1 middle finger). Patients experienced pain, swelling, and discomfort around the site of puncture immediately after the injury. These initial symptoms subsided within a few days, and secondary symptoms including fusiform swelling, limited motion, and mild pain of the PIP joint appeared from 1 to 2 months later. Laboratory tests of inflammation and blood cell counts were negative. Plain radiographs showed soft tissue swelling and osteolysis but no visible spine. Thorough synovectomy of the PIP joint was performed, and the granulation tissue around the joint was also removed. No microorganism was identified from tissue culture or polymerase chain reaction in any of the 5 patients. At a mean follow-up of 21 months, 2 patients exhibited essentially normal active motion of the affected PIP joint, whereas the remaining 3 patients had diminished range of motion. Diagnosis of sea urchin spine arthritis can be made by history of sea urchin spine injury, a symptom-free period before the development of synovitis, and the absence of laboratory test abnormalities. Neither antibiotics nor nonsteroidal anti-inflammatory agents are effective. Undertaken early enough, thorough synovectomy might avoid complications and obtain favorable results. Therapeutic IV.

First report of antennular attachment organs in a barnacle nauplius larva

AbstractLarvae released from Newmaniverruca albatrossiana were cultured in the laboratory until the cypris stage. The brood size of individuals was low, about 60 larvae per brood. The exact number of instars was not determined. Early instars had the morphology normally seen in lecithotrophic nauplii of thoracican cirripedes. They had uniramous antennules with a few apical setae and biramous antennae and mandibles equipped with natatory setae only. Neither antennae nor mandibles carried any enditic spines or setae and the mouth cone was diminutive. The last nauplius stage obtained in our cultures was typical except in the structure of antennules. The head shield was enlarged but not flexed down, the antennae and mandibles were virtually unchanged from earlier instars, and the ventral thoracic process was well developed but without any external appendages. In contrast, the antennules had the complex shape and segmentation otherwise seen only in cypris larvae, where they are used for bipedal walking on the substratum in search of a settlement site. The similarity included the specialized shape of the first two antennular segments and the specialization of the third as an attachment organ. Nauplii just prior to this last instar had simple, straight antennules but completely lacked setae and instead terminated bluntly in what appears to be an incipient attachment organ. The presence of cypris‐like antennules in late nauplii has not previously been recorded in cirripedes. We suggest that this will allow the larvae to attach on the substratum temporarily before they reach the cypris instar and this will increase the chance of settling successfully on their rare substratum (sea urchin spines). The specialization in late N. albatrossiana nauplii will therefore decrease mortality during the larval phase and thus counterbalance the very low breeding potential in this deep‐sea species.

Conversion of sea urchin spines to Mg-substituted tricalcium phosphate for bone implants

The skeleton of sea urchin spines is composed of large single crystals of Mg-rich calcite, which have smooth, continuously curved surfaces and form a three-dimensional fenestrated mineral network. Spines of the echinoids Heterocentrotus trigonarius and Heterocentrotus mammillatus were converted by the hydrothermal reaction at 180 °C to bioresorbable Mg-substituted tricalcium phosphate (β-TCMP). Due to the presence of Mg in the calcite lattice, conversion to β-TCMP occurs preferentially to hydroxyapatite formation. The converted β-TCMP still maintains the three-dimensional interconnected porous structures of the original spine. The main conversion mechanism is the ion-exchange reaction, although there is also a dissolution–reprecipitation process that forms some calcium phosphate precipitates on the surfaces of the spine network. The average fracture strength of urchin spines and converted spines (β-TCMP) in the compression tests are 42 and 23 MPa, respectively. In vivo studies using a rat model demonstrated new bone growth up to and around the β-TCMP implants after implantation in rat femoral defects for 6 weeks. Some new bone was found to migrate through the spine structural pores, starting from the outside of the implant through the pores at the edge of the implants. These results indicate good bioactivity and osteoconductivity of the porous β-TCMP implants.

Sea urchin granuloma

Injuries caused by venomous and poisonous aquatic animals may provoke important morbidity in humans. The phylum Echinoderma include more than 6000 species of starfish, sea urchins, sand dollars, and sea cucumbers some of which have been found responsible for injuries to humans. Initial injuries by sea urchins are associated with trauma and envenomation, but later effects can be observed. Sea urchin granuloma is a chronic granulomatous skin disease caused by frequent and successive penetration of sea urchin spines which have not been removed from wounds. The authors report a typical case of sea urchin granuloma in a fisherman and its therapeutic implications.

Uniform Hexagonal Plates of Vaterite CaCO3 Mesocrystals Formed by Biomimetic Mineralization

AbstractVaterite mesocrystals with hexagonal morphology and uniform size have been successfully synthesized in the presence of a N‐trimethylammonium derivative of hydroxyethyl cellulose via aggregation‐mediated crystallization using a simple gas‐diffusion method. The uniform hexagonal plates display sharp facets and edges, even though they are formed by the aggregation of nanocrystals. The results demonstrate that each vaterite plate can be explained as consisting of aggregates of nanoparticles that share the same three‐dimensional orientation. A mechanism for the formation of hexagonal vaterite mesocrystals made of primary nanoparticles and hexagonal units is also presented. An understanding of the mesoscale transformation process will be helpful in controlling the aggregation‐driven formation of complex higher‐order structured materials and will provide new insights into biomineralization mechanisms. For example, the spines of sea urchins can be discussed within the framework of the mesocrystal concept. This study could provide an additional tool for designing advanced materials and could be used for the synthesis of more complex crystalline three‐dimensional structures.

Molding Mineral within Microporous Hydrogels by a Polymer-Induced Liquid-Precursor (PILP) Process

Natural biominerals often have exquisite morphologies, where the cells exercise a high degree of crystallographic control through secretion of biological macromolecules and regulation of ion transport. One important example is the sea urchin spine. It has recently been shown to be formed through deposition of a transient amorphous calcium carbonate (ACC) precursor phase that later transforms to single-crystalline calcite, ultimately forming an elaborate three-dimensional microporous calcium carbonate structure with interconnected pores. Macromolecules associated with the mineral phase are thought to play a key role in regulating this transformation. The work described here mimics this type of morphological control by "molding" an amorphous calcium carbonate precursor within a porous poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogel that has been prepared as a negative replica from the void space of an urchin spine. Using an acidic biomimetic polymer as a process-directing agent, we show that polyaspartic acid induces amorphous calcium carbonate (ACC) nanoparticles, which have fluidic character and therefore are able to infiltrate the PHEMA hydrogel replica and coalesce into the convoluted morphology that replicates the original microporous structure of the sea urchin spine. By "molding" calcium carbonate into a complex morphology at room temperature, using a precursor process that is induced by a biomimetic acidic macromolecule, the PILP process is a useful in vitro model for examining different aspects of the amorphous-to-crystalline transformation process that is apparently used by a variety of biomineralizing organisms. For example, although we were able to replicate the overall morphology of the spine, it had polycrystalline texture; further studies with this system will focus on controlling the nucleation event, which may help to elucidate how such a convoluted structure can be prepared with single-crystalline texture via an amorphous precursor. Through a better understanding of the mechanisms used by organisms to regulate crystal properties, such biomimetic processes can lead to the synthesis of materials with superior electronic, mechanical, and optical properties.

An effective alternative management for multiple sea urchin spine injury: Erbium–YAG laser ablation

Complete surgical removal of sea urchin spines can be extremely difficult due to the multiplicity and fragility of the spines. We describe a 49-year-old lady with multiple sea urchin spine injury over her left sole which was successfully treated with Erbium–YAG laser therapy. Laser ablation is very effective in destroying multiple sea urchin spines without causing thermal necrosis of the adjacent tissues, and may be considered as an important non-operative treatment modality.

The Management of Hand Injuries Caused by Sea Urchin Spines

Injuries to the hand by sea urchin spines are not commonly seen in the United Kingdom. There are many varieties of sea urchins (Echinoidea) throughout the world. They have a spherical calcium carbonate exoskeleton covered with spines. Certain varieties may be venomous, in particular the flower urchin (Toxopneustes pileolus) found in the Indo-Pacific oceans. Injury may also be caused by the urchin spines or pedicellaria (delicate seizing organs equipped with jaws). A small number of hand injuries associated with sea urchin spines have been reported in the literature.

Mechanical Properties of the Isolated Catch Apparatus of the Sea Urchin Spine Joint: Muscle Fibers Do Not Contribute to Passive Stiffness Changes

The catch apparatus (CA) is the collagenous ligament at the spinal joint of sea urchins. It maintains spine posture by stiffening and allows spine movement by softening. A CA preparation, which was isolated from ossicles, was used to test the hypothesis that frictional forces between collagen fibers and ossicles are the source of stiffness changes. Isolated preparations of the CA changed in stiffness, thus falsifying the hypothesis. Another hypothesis proposes that muscle fibers, which represent a relatively small component of the CA, cause stiffening of the CA by contraction. Chemicals that evoked contraction in spine muscles did not always stiffen the CA: the CA of Heterocentrotus mammillatus softened in response to artificial seawater with potassium concentration elevated to 100 mM. This provided evidence against the muscle-based hypothesis. The present results suggest that the stiffness changes of the CA are based on changes in the mechanical properties of the extracellular components of the connective tissue and are therefore related to the connective tissue catch that is widespread in other echinoderms.

Sea Urchin Spine Calcite Forms via a Transient Amorphous Calcium Carbonate Phase

The skeletons of adult echinoderms comprise large single crystals of calcite with smooth convoluted fenestrated morphologies, raising many questions about how they form. By using water etching, infrared spectroscopy, electron diffraction, and environmental scanning electron microscopy, we show that sea urchin spine regeneration proceeds via the initial deposition of amorphous calcium carbonate. Because most echinoderms produce the same type of skeletal material, they probably all use this same mechanism. Deposition of transient amorphous phases as a strategy for producing single crystals with complex morphology may have interesting implications for the development of sophisticated materials.

Single crystal structure analysis of sea urchin spine calcites: Systematic investigations of the Ca/Mg distribution as a function of habitat of the sea urchin and the sample location in the spine

The hard skeleton of sea urchin spines consists of a monolithic single crystalline magnesian calcite with typical contents of MgCO 3 ranging from 2 to 12 mol% and about 0.1 weight% of occluded organic macromolecules. These macromolecules take effect on the calcite crystal growth, forming the spine shape in a porous spongy structure crossed by filled wedges of calcite radially arranged about the long axis of the spine. The single crystal structure analysis and polarization microscopy confirm the perfect alignment of the crystallites, thus the spine is a single crystal of calcite with the spine axis along the crystallographic c-axis, in agreement with earlier experiments. The magnesium content of the skeletal parts of the sea urchin is approximately linearly related with the water temperature of the sea urchin habitat. Elemental and chemical analysis showed an inhomogeneous Mg distribution in single spines: The Mg content increases from the spine-tip to the base by about 2 mol% at average. This structural inhomogeneity leads to a solid solution hardening of the material by the statistical incorporation of Mg 2+ ions in a crystal structure. The size difference between Ca 2+ and Mg 2+ ions impedes the propagation of cracks, thus affecting the fracture behavior of the biogenic calcite, which is conchoidal in contrast to the perfect {10.4} cleavage of geological calcite. The accumulation of Mg in the spine-base most likely serves to enhance this effect and thus strengthens the spine close to the shell.

Recent Studies on the Pathological Effects of Purified Sea Urchin Toxins

Sea urchins are the popular name for marine invertebrates that belong to the phylum Echinodermata. Approximately 200 species of sea urchin are found on the coast of Japan, while several species of echinoids are dangerous to humans. Envenomations are caused by stings from either pedicellariae or spines. In our search for bioactive compounds we have been investigating mitogenicity and/or cytotoxicity from the venoms of the four sea urchins: Toxopneustes pileolus, Tripneustes gratilla, Diadema setosum, and Asthenosoma species. The toxopneustid sea urchins have well‐developed globiferous pedicellariae with bioactive substances. The hollow primary spines of diadematid sea urchins are suggested to contain bioactive substances. Two D‐galactose‐binding lectins (SUL‐I and SUL‐II ) and a heparin‐binding lectin (TGL‐I) were purified from the globiferous pedicellariae of T. pileolus and T. gratilla. Furthermore, a novel hemolytic lectin with a molecular mass of 29 kDa was isolated from the coelomic fluid of T. gratil...

Sea Urchin Mineralized Tissue

AbstractSea urchin ossicles are structural analogs of mammalian bones and serve as a model biomineral system. Sea urchins employ as wide a range of composite reinforcement strategies as are seen in engineering composites, and, studied as materials, teeth (and other ossicles) from different echinoid families illustrate combinations of reinforcement parameters and toughening mechanisms providing good functionality. Studying ossicles from different sea urchin families, therefore, is one method of probing the composite design space available to sea urchins, and this offers important guidance for engineering of structural tissue. This report is part of a larger multi-mode x-ray investigation employing microCT, both synchrotron and laboratory sources, phase contrast radiography and transmission microbeam diffraction mapping; voxels (volume elements) approaching 1 μm3 can be interrogated noninvasively in millimeter sized samples. Only microCT results are presented below; these focus on sea urchin lanterns (jaw structure) and spines of a variety of sea urchin types and serve to illustrate how this sort of integrated approach might be applied to bone.

Identification of a "glycine-loop"-like coiled structure in the 34 AA Pro,Gly,Met repeat domain of the biomineral-associated protein, PM27.

Fracture resistance in biomineralized structures has been linked to the presence of proteins, some of which possess sequences that are associated with elastic behavior. One such protein superfamily, the Pro,Gly-rich sea urchin intracrystalline spicule matrix proteins, form protein-protein supramolecular assemblies that modify the microstructure and fracture-resistant properties of the calcium carbonate mineral phase within embryonic sea urchin spicules and adult sea urchin spines. In this report, we detail the identification of a repetitive keratin-like "glycine-loop"- or coil-like structure within the 34-AA (AA: amino acid) N-terminal domain, (PGMG)(8)PG, of the spicule matrix protein, PM27. The identification of this repetitive structural motif was accomplished using two capped model peptides: a 9-AA sequence, GPGMGPGMG, and a 34-AA peptide representing the entire motif. Using CD, NMR spectrometry, and molecular dynamics simulated annealing/minimization simulations, we have determined that the 9-AA model peptide adopts a loop-like structure at pH 7.4. The structure of the 34-AA polypeptide resembles a coil structure consisting of repeating loop motifs that do not exhibit long-range ordering. Given that loop structures have been associated with protein elastic behavior and protein motion, it is plausible that the 34-AA Pro,Gly,Met repeat sequence motif in PM27 represents a putative elastic or mobile domain.

Identification of Mycobacterium marinum in sea-urchin granulomas.

Sea-urchin granuloma is a chronic granulomatous reaction arising after injury with sea-urchin spines. Classified as an allergic foreign-body type of granuloma, it is believed to be a delayed-type reaction to an as yet unidentified antigen. In a clinicopathological study, 50 biopsy specimens from 35 patients diagnosed as having sea-urchin granuloma caused by Paracentrotus lividus, we found different inflammatory patterns that in some cases suggested a mycobacterial infection. To investigate and identify mycobacterial DNA in formalin-fixed and paraffin-embedded skin biopsy specimens diagnosed as sea-urchin granulomas. A search combining polymerase chain reaction amplification using Mycobacterium genus-specific primers, and subsequent restriction enzyme analysis enabling identification to the species level, was performed in 41 samples. Amplification of a 924-bp DNA fragment encoding mycobacterial 16S rRNA gene was positive in eight biopsy specimens from seven patients (21%). M. marinum-specific restriction patterns were identified in three samples. Although further controlled studies are necessary, from these data it would appear that mycobacteria may play a pathogenic role in some cases of sea-urchin granuloma.

Sea-urchin granuloma: histologic profile. A pathologic study of 50 biopsies.

Sea-urchin granuloma is a chronic granulomatous skin lesion caused by injury with sea-urchin spines. Frequently these lesions occur on the hands and develop several months after the initial injury. Classified as an allergic foreign-body reaction, their most common histological pattern resembles sarcoid. The purpose of this study was to evaluate the light microscopic features of biopsies from lesions clinically diagnosed of sea-urchin granolomas. We retrospectively reviewed 50 biopsy specimens corresponding to 35 patients with sea-urchin granulomas. These lesions were caused by injuries with the spines of the sea-urchin Paracentrotus lividus. Data were collected between 1990 and 1999 from patients in the seashore of Galicia (NW Atlantic coast, Spain). The cohort consisted of 35 patients (31 males, 4 females), with a median age of 35 years (range 14-60 years). The median duration of the disease was 7.5 months (range 2-60 months). We identified different histopathologic patterns. A granulomatous reaction was observed in 39 biopsies (78%). In 70% corresponding to 35 biopsies this granulomatous reaction was predominant. Foreign-body, sarcoidal, tuberculoid, necrobiotic and suppurative granulomas were identified. The remaining 15 biopsies (30%) showed a predominant inflammatory reaction with features of non-specific chronic inflammation or suppurative dermatitis. A panel of histopathologic features, including epidermal and dermal changes were evaluated. Presence of focal necrosis and microabscesses were common findings. In 50% of our specimens we found umbilication and/or perforation. Additional features included the presence of inclusion epidermoid cysts in four cases and squamous syringometaplasia in one case. Our observations suggest that sea-urchin granuloma span a wide morphologic spectrum. A granulomatous inflammatory reaction was predominant, with the foreign body and sarcoidal types the most frequent patterns. Other histopathologic patterns with non granulomatous inflammation can be noted. Some features, such as the frequency of perforation and the presence of necrobiotic granulomas have not previously been recognized in the literature.

Accumulation of Pb and Zn in Sea Urchin Plates and Spines Related to their Different Crystalline Structure

Accumulation of Pb and Zn in Sea Urchin Plates and Spines Related to their Different Crystalline Structure

Glycerinated Catch Apparatus of Sea Urchin Spines: the Effects of Cations on its Mechanical Properties and Ultrastructure

Sea urchin spinal ligaments (the catch apparatus) were extracted with glycerin, and electron microscopic observations comfirmed that no cell membranes remained intact after glycerination. We studied the effects of cations (Na(+), K(+), Ca(2+), Mg(2+)) on the mechanical properties of the glycerinated ligaments. Monovalent cations decreased whereas divalent cations increased the viscosity of the ligaments. The ion dependencies were similar to previous results with detergent-extracted holothurian dermis, which suggests that the echinoid ligament shares a similar mechanism for changes in mechanical properties with other catch connective tissues. This provides evidence against the hypothesis of that muscles in the catch apparatus are responsible for the changes in mechanical properties of the ligament. Fine projections cross-bridging collagen fibrils were observed in the glycerin-extracted ligaments as well as in the intact ligaments. They were found in all the ionic conditions studied.

Arthrites, ténosynovite, fasciite et bursite à piquants d'oursins. À propos d'une série de 12 observations réunionnaises

Arthritis, tenosynovitis, and bursitis due to sea urchin spine injuries have unique pathological features and run a chronic course until the spines are removed. Of the 40 cases of sea urchin spine-related clinical symptoms published to date, only 12 had osteoarticular symptoms. Patients and methods. We studied 12 cases with osteoarticular symptoms seen in Réunion Island from 1994 to 1998. There were nine cases of arthritis and one case each of tenosynovitis, fasciitis, and bursitis. The nine males and three females had an age range of 9 to 50 years. Results. The injury was at the knee in six cases, the foot in three, and the hand in three. The time from injury to lesion development ranged from two days to two and a half months. Laboratory tests were normal apart from evidence of mild inflammation in three of the arthritis cases. The spine was visible on plain radiographs in eight cases. Histology was done in seven patients and consistently showed a typical foreign body granuloma. Removal of the spine with synovectomy was performed in 11 cases and consistently ensured a full recovery. Discussion. The clinical manifestations and management in our patients were compared to those in earlier reports. The differential diagnosis of laboratory test, radiographic, and histologic findings is reviewed. Pathogenic hypotheses and the immunogenic effect of the protein sheath that surrounds sea urchin spines are discussed. Conclusion. The diagnosis of these frequently underrecognized lesions rests on a careful history and on converging histologic, radiologic, and clinical findings. Surgery is always needed and ensures a full recovery.